#!/usr/bin/env python3
"""
Internal utilities.
"""
# Import statements
import inspect
from numbers import Integral, Real

import numpy as np
from matplotlib import rcParams as rc_matplotlib

try:  # print debugging (used with internal modules)
    from icecream import ic
except ImportError:  # graceful fallback if IceCream isn't installed
    ic = lambda *args: print(*args)  # noqa: E731


def _not_none(*args, default=None, **kwargs):
    """
    Return the first non-``None`` value. This is used with keyword arg aliases and
    for setting default values. Use `kwargs` to issue warnings when multiple passed.
    """
    first = default
    if args and kwargs:
        raise ValueError('_not_none can only be used with args or kwargs.')
    elif args:
        for arg in args:
            if arg is not None:
                first = arg
                break
    elif kwargs:
        for name, arg in list(kwargs.items()):
            if arg is not None:
                first = arg
                break
        kwargs = {name: arg for name, arg in kwargs.items() if arg is not None}
        if len(kwargs) > 1:
            warnings._warn_proplot(
                f'Got conflicting or duplicate keyword arguments: {kwargs}. '
                'Using the first keyword argument.'
            )
    return first


# Internal import statements
# WARNING: Must come after _not_none because this is leveraged inside other funcs
from . import (  # noqa: F401
    benchmarks,
    context,
    docstring,
    fonts,
    guides,
    inputs,
    labels,
    rcsetup,
    versions,
    warnings
)
from .versions import _version_mpl, _version_cartopy  # noqa: F401
from .warnings import ProplotWarning  # noqa: F401


# Style aliases. We use this rather than matplotlib's normalize_kwargs and _alias_maps.
# NOTE: We add aliases 'edgewidth' and 'fillcolor' for patch edges and faces
# NOTE: Alias cannot appear as key or else _translate_kwargs will overwrite with None!
_alias_maps = {
    'rgba': {
        'red': ('r',),
        'green': ('g',),
        'blue': ('b',),
        'alpha': ('a',),
    },
    'hsla': {
        'hue': ('h',),
        'saturation': ('s', 'c', 'chroma'),
        'luminance': ('l',),
        'alpha': ('a',),
    },
    'patch': {
        'alpha': ('a', 'alphas', 'fa', 'facealpha', 'facealphas', 'fillalpha', 'fillalphas'),  # noqa: E501
        'color': ('c', 'colors'),
        'edgecolor': ('ec', 'edgecolors'),
        'facecolor': ('fc', 'facecolors', 'fillcolor', 'fillcolors'),
        'hatch': ('h', 'hatching'),
        'linestyle': ('ls', 'linestyles'),
        'linewidth': ('lw', 'linewidths', 'ew', 'edgewidth', 'edgewidths'),
        'zorder': ('z', 'zorders'),
    },
    'line': {  # copied from lines.py but expanded to include plurals
        'alpha': ('a', 'alphas'),
        'color': ('c', 'colors'),
        'dashes': ('d', 'dash'),
        'drawstyle': ('ds', 'drawstyles'),
        'fillstyle': ('fs', 'fillstyles', 'mfs', 'markerfillstyle', 'markerfillstyles'),
        'linestyle': ('ls', 'linestyles'),
        'linewidth': ('lw', 'linewidths'),
        'marker': ('m', 'markers'),
        'markersize': ('s', 'ms', 'markersizes'),  # WARNING: no 'sizes' here for barb
        'markeredgewidth': ('ew', 'edgewidth', 'edgewidths', 'mew', 'markeredgewidths'),
        'markeredgecolor': ('ec', 'edgecolor', 'edgecolors', 'mec', 'markeredgecolors'),
        'markerfacecolor': (
            'fc', 'facecolor', 'facecolors', 'fillcolor', 'fillcolors',
            'mc', 'markercolor', 'markercolors', 'mfc', 'markerfacecolors'
        ),
        'zorder': ('z', 'zorders'),
    },
    'collection': {  # WARNING: face color ignored for line collections
        'alpha': ('a', 'alphas'),  # WARNING: collections and contours use singular!
        'colors': ('c', 'color'),
        'edgecolors': ('ec', 'edgecolor', 'mec', 'markeredgecolor', 'markeredgecolors'),
        'facecolors': (
            'fc', 'facecolor', 'fillcolor', 'fillcolors',
            'mc', 'markercolor', 'markercolors', 'mfc', 'markerfacecolor', 'markerfacecolors'  # noqa: E501
        ),
        'linestyles': ('ls', 'linestyle'),
        'linewidths': ('lw', 'linewidth', 'ew', 'edgewidth', 'edgewidths', 'mew', 'markeredgewidth', 'markeredgewidths'),  # noqa: E501
        'marker': ('m', 'markers'),
        'sizes': ('s', 'ms', 'markersize', 'markersizes'),
        'zorder': ('z', 'zorders'),
    },
    'text': {
        'color': ('c', 'fontcolor'),  # NOTE: see text.py source code
        'fontfamily': ('family', 'name', 'fontname'),
        'fontsize': ('size',),
        'fontstretch': ('stretch',),
        'fontstyle': ('style',),
        'fontvariant': ('variant',),
        'fontweight': ('weight',),
        'fontproperties': ('fp', 'font', 'font_properties'),
        'zorder': ('z', 'zorders'),
    },
}


# Unit docstrings
# NOTE: Try to fit this into a single line. Cannot break up with newline as that will
# mess up docstring indentation since this is placed in indented param lines.
_units_docstring = 'If float, units are {units}. If string, interpreted by `~proplot.utils.units`.'  # noqa: E501
docstring._snippet_manager['units.pt'] = _units_docstring.format(units='points')
docstring._snippet_manager['units.in'] = _units_docstring.format(units='inches')
docstring._snippet_manager['units.em'] = _units_docstring.format(units='em-widths')


# Style docstrings
# NOTE: These are needed in a few different places
_line_docstring = """
lw, linewidth, linewidths : unit-spec, default: :rc:`lines.linewidth`
    The width of the line(s).
    %(units.pt)s
ls, linestyle, linestyles : str, default: :rc:`lines.linestyle`
    The style of the line(s).
c, color, colors : color-spec, optional
    The color of the line(s). The property `cycle` is used by default.
a, alpha, alphas : float, optional
    The opacity of the line(s). Inferred from `color` by default.
"""
_patch_docstring = """
lw, linewidth, linewidths : unit-spec, default: :rc:`patch.linewidth`
    The edge width of the patch(es).
    %(units.pt)s
ls, linestyle, linestyles : str, default: '-'
    The edge style of the patch(es).
ec, edgecolor, edgecolors : color-spec, default: '{edgecolor}'
    The edge color of the patch(es).
fc, facecolor, facecolors, fillcolor, fillcolors : color-spec, optional
    The face color of the patch(es). The property `cycle` is used by default.
a, alpha, alphas : float, optional
    The opacity of the patch(es). Inferred from `facecolor` and `edgecolor` by default.
"""
_pcolor_collection_docstring = """
lw, linewidth, linewidths : unit-spec, default: 0.3
    The width of lines between grid boxes.
    %(units.pt)s
ls, linestyle, linestyles : str, default: '-'
    The style of lines between grid boxes.
ec, edgecolor, edgecolors : color-spec, default: 'k'
    The color of lines between grid boxes.
a, alpha, alphas : float, optional
    The opacity of the grid boxes. Inferred from `cmap` by default.
"""
_contour_collection_docstring = """
lw, linewidth, linewidths : unit-spec, default: 0.3 or :rc:`lines.linewidth`
    The width of the line contours. Default is ``0.3`` when adding to filled contours
    or :rc:`lines.linewidth` otherwise. %(units.pt)s
ls, linestyle, linestyles : str, default: '-' or :rc:`contour.negative_linestyle`
    The style of the line contours. Default is ``'-'`` for positive contours and
    :rcraw:`contour.negative_linestyle` for negative contours.
ec, edgecolor, edgecolors : color-spec, default: 'k' or inferred
    The color of the line contours. Default is ``'k'`` when adding to filled contours
    or inferred from `color` or `cmap` otherwise.
a, alpha, alpha : float, optional
    The opacity of the contours. Inferred from `edgecolor` by default.
"""
_text_docstring = """
name, fontname, family, fontfamily : str, optional
    The font typeface name (e.g., ``'Fira Math'``) or font family name (e.g.,
    ``'serif'``). Matplotlib falls back to the system default if not found.
size, fontsize : unit-spec or str, optional
    The font size. %(units.pt)s
    This can also be a string indicating some scaling relative to
    :rcraw:`font.size`. The sizes and scalings are shown below. The
    scalings ``'med'``, ``'med-small'``, and ``'med-large'`` are
    added by proplot while the rest are native matplotlib sizes.

    .. _font_table:

    ==========================  =====
    Size                        Scale
    ==========================  =====
    ``'xx-small'``              0.579
    ``'x-small'``               0.694
    ``'small'``, ``'smaller'``  0.833
    ``'med-small'``             0.9
    ``'med'``, ``'medium'``     1.0
    ``'med-large'``             1.1
    ``'large'``, ``'larger'``   1.2
    ``'x-large'``               1.440
    ``'xx-large'``              1.728
    ``'larger'``                1.2
    ==========================  =====

"""
docstring._snippet_manager['artist.line'] = _line_docstring
docstring._snippet_manager['artist.text'] = _text_docstring
docstring._snippet_manager['artist.patch'] = _patch_docstring.format(edgecolor='none')
docstring._snippet_manager['artist.patch_black'] = _patch_docstring.format(edgecolor='black')  # noqa: E501
docstring._snippet_manager['artist.collection_pcolor'] = _pcolor_collection_docstring
docstring._snippet_manager['artist.collection_contour'] = _contour_collection_docstring


def _get_aliases(category, *keys):
    """
    Get all available aliases.
    """
    aliases = []
    for key in keys:
        aliases.append(key)
        aliases.extend(_alias_maps[category][key])
    return tuple(aliases)


def _kwargs_to_args(options, *args, allow_extra=False, **kwargs):
    """
    Translate keyword arguments to positional arguments. Permit omitted
    arguments so that plotting functions can infer values.
    """
    nargs, nopts = len(args), len(options)
    if nargs > nopts and not allow_extra:
        raise ValueError(f'Expected up to {nopts} positional arguments. Got {nargs}.')
    args = list(args)  # WARNING: Axes.text() expects return type of list
    args.extend(None for _ in range(nopts - nargs))  # fill missing args
    for idx, keys in enumerate(options):
        if isinstance(keys, str):
            keys = (keys,)
        opts = {}
        if args[idx] is not None:  # positional args have first priority
            opts[keys[0] + '_positional'] = args[idx]
        for key in keys:  # keyword args
            opts[key] = kwargs.pop(key, None)
        args[idx] = _not_none(**opts)  # may reassign None
    return args, kwargs


def _pop_kwargs(kwargs, *keys, **aliases):
    """
    Pop the input properties and return them in a new dictionary.
    """
    output = {}
    aliases.update({key: () for key in keys})
    for key, aliases in aliases.items():
        aliases = (aliases,) if isinstance(aliases, str) else aliases
        aliases = tuple(alias for alias in aliases if alias != key)  # prevent dev errs
        opts = {key: kwargs.pop(key, None) for key in (key, *aliases)}
        value = _not_none(**opts)
        if value is not None:
            output[key] = value
    return output


def _pop_params(kwargs, *funcs, ignore_internal=False):
    """
    Pop parameters of the input functions or methods.
    """
    internal_params = {
        'default_cmap',
        'default_discrete',
        'inbounds',
        'plot_contours',
        'plot_lines',
        'skip_autolev',
        'to_centers',
    }
    output = {}
    for func in funcs:
        if isinstance(func, inspect.Signature):
            sig = func
        elif callable(func):
            sig = inspect.signature(func)
        elif func is None:
            continue
        else:
            raise RuntimeError(f'Internal error. Invalid function {func!r}.')
        for key in sig.parameters:
            value = kwargs.pop(key, None)
            if ignore_internal and key in internal_params:
                continue
            if value is not None:
                output[key] = value
    return output


def _pop_props(input, *categories, prefix=None, ignore=None, skip=None):
    """
    Pop the registered properties and return them in a new dictionary.
    """
    output = {}
    skip = skip or ()
    ignore = ignore or ()
    if isinstance(skip, str):  # e.g. 'sizes' for barbs() input
        skip = (skip,)
    if isinstance(ignore, str):  # e.g. 'marker' to ignore marker properties
        ignore = (ignore,)
    prefix = prefix or ''  # e.g. 'box' for boxlw, boxlinewidth, etc.
    for category in categories:
        for key, aliases in _alias_maps[category].items():
            if isinstance(aliases, str):
                aliases = (aliases,)
            opts = {
                prefix + alias: input.pop(prefix + alias, None)
                for alias in (key, *aliases)
                if alias not in skip
            }
            prop = _not_none(**opts)
            if prop is None:
                continue
            if any(string in key for string in ignore):
                warnings._warn_proplot(f'Ignoring property {key}={prop!r}.')
                continue
            if isinstance(prop, str):  # ad-hoc unit conversion
                if key in ('fontsize',):
                    from ..utils import _fontsize_to_pt
                    prop = _fontsize_to_pt(prop)
                if key in ('linewidth', 'linewidths', 'markersize'):
                    from ..utils import units
                    prop = units(prop, 'pt')
            output[key] = prop
    return output


def _pop_rc(src, *, ignore_conflicts=True):
    """
    Pop the rc setting names and mode for a `~Configurator.context` block.
    """
    # NOTE: Must ignore deprected or conflicting rc params
    # NOTE: rc_mode == 2 applies only the updated params. A power user
    # could use ax.format(rc_mode=0) to re-apply all the current settings
    conflict_params = (
        'alpha',
        'color',
        'facecolor',
        'edgecolor',
        'linewidth',
        'basemap',
        'backend',
        'share',
        'span',
        'tight',
        'span',
    )
    kw = src.pop('rc_kw', None) or {}
    if 'mode' in src:
        src['rc_mode'] = src.pop('mode')
        warnings._warn_proplot(
            "Keyword 'mode' was deprecated in v0.6. Please use 'rc_mode' instead."
        )
    mode = src.pop('rc_mode', None)
    mode = _not_none(mode, 2)  # only apply updated params by default
    for key, value in tuple(src.items()):
        name = rcsetup._rc_nodots.get(key, None)
        if ignore_conflicts and name in conflict_params:
            name = None  # former renamed settings
        if name is not None:
            kw[name] = src.pop(key)
    return kw, mode


def _translate_loc(loc, mode, *, default=None, **kwargs):
    """
    Translate the location string `loc` into a standardized form. The `mode`
    must be a string for which there is a :rcraw:`mode.loc` setting. Additional
    options can be added with keyword arguments.
    """
    # Create specific options dictionary
    # NOTE: This is not inside validators.py because it is also used to
    # validate various user-input locations.
    if mode == 'align':
        loc_dict = rcsetup.ALIGN_LOCS
    elif mode == 'panel':
        loc_dict = rcsetup.PANEL_LOCS
    elif mode == 'legend':
        loc_dict = rcsetup.LEGEND_LOCS
    elif mode == 'colorbar':
        loc_dict = rcsetup.COLORBAR_LOCS
    elif mode == 'text':
        loc_dict = rcsetup.TEXT_LOCS
    else:
        raise ValueError(f'Invalid mode {mode!r}.')
    loc_dict = loc_dict.copy()
    loc_dict.update(kwargs)

    # Translate location
    if loc in (None, True):
        loc = default
    elif isinstance(loc, (str, Integral)):
        try:
            loc = loc_dict[loc]
        except KeyError:
            raise KeyError(
                f'Invalid {mode} location {loc!r}. Options are: '
                + ', '.join(map(repr, loc_dict))
                + '.'
            )
    elif (
        mode == 'legend'
        and np.iterable(loc)
        and len(loc) == 2
        and all(isinstance(l, Real) for l in loc)
    ):
        loc = tuple(loc)
    else:
        raise KeyError(f'Invalid {mode} location {loc!r}.')

    # Kludge / white lie
    # TODO: Implement 'best' colorbar location
    if mode == 'colorbar' and loc == 'best':
        loc = 'lower right'

    return loc


def _translate_grid(b, key):
    """
    Translate an instruction to turn either major or minor gridlines on or off into a
    boolean and string applied to :rcraw:`axes.grid` and :rcraw:`axes.grid.which`.
    """
    ob = rc_matplotlib['axes.grid']
    owhich = rc_matplotlib['axes.grid.which']

    # Instruction is to turn off gridlines
    if not b:
        # Gridlines are already off, or they are on for the particular
        # ones that we want to turn off. Instruct to turn both off.
        if (
            not ob
            or key == 'grid' and owhich == 'major'
            or key == 'gridminor' and owhich == 'minor'
        ):
            which = 'both'  # disable both sides
        # Gridlines are currently on for major and minor ticks, so we
        # instruct to turn on gridlines for the one we *don't* want off
        elif owhich == 'both':  # and ob is True, as already tested
            # if gridminor=False, enable major, and vice versa
            b = True
            which = 'major' if key == 'gridminor' else 'minor'
        # Gridlines are on for the ones that we *didn't* instruct to
        # turn off, and off for the ones we do want to turn off. This
        # just re-asserts the ones that are already on.
        else:
            b = True
            which = owhich

    # Instruction is to turn on gridlines
    else:
        # Gridlines are already both on, or they are off only for the
        # ones that we want to turn on. Turn on gridlines for both.
        if (
            owhich == 'both'
            or key == 'grid' and owhich == 'minor'
            or key == 'gridminor' and owhich == 'major'
        ):
            which = 'both'
        # Gridlines are off for both, or off for the ones that we
        # don't want to turn on. We can just turn on these ones.
        else:
            which = owhich

    return b, which
